ec2_host_key module

Adds a new module for retrieving the ssh host key from an EC2 instance
and updates the known hosts file. Useful if you want to use strict
host key checking when ssh'ing to EC2 instances.

This module retrieves the instance host key by retrieving the console
log using the EC2 API and parses out the host key. Therefore, this
module requires that the VM image is configured to write the host key
out to the console.